Programming Reference Guide
Quick access to syntax, commands, and concepts for all major programming languages.
HTML Reference
Quick reference for HTML syntax and commands
Tag
Description
Example
<!DOCTYPE html>
Defines the document type
<!DOCTYPE html>
<html>
Root element of an HTML page
<html lang=”en”>
<head>
Contains metadata about the document
<head>…</head>
<body>
Contains the visible page content
<body>…</body>
<h1> to <h6>
HTML headings
<h1>Title</h1>
<p>
Paragraph
<p>Text here</p>
<a>
Hyperlink
<a href=”url”>Link</a>
<img>
Image
<img src=”image.jpg” alt=”desc”>
<div>
Division or section
<div class=”container”>
<table>
Inline container
<span class=”highlight”>
<table>
Table
<table>…</table>
<form>
Form for user input
<form action=”/submit”>
<input>
Input field
<input type=”text”>
<button>
Clickable button
<button>Click</button>
<ul>
Unordered list
<ul><li>Item</li></ul>
<ol>
Ordered
<ol><li>Item 1</li></ol>
CSS Reference
Quick reference for CSS syntax and commands
Tag
Description
Example
font-size
Text size
font-size: 16px;
font-family
Font family
font-family: Arial;
margin
Outer spacing
<h1>Title</h1>
padding
Inner spacing
padding: 20px;
border
Hyperlink
border: 1px solid #000;
position
Positioning method
position: relative;
width
Element width
width: 100%;
height
Element height
<span class=”highlight”>
<table>
Table
height: 50px;
flex
Flexbox properties
flex: 1;
grid
Input field
<input type=”text”>
animation
Animation properties
animation: fadeIn 1s;
transition
Transition effects
transition: all 0.3s;
JavaScript Reference
Quick reference for JavaScript syntax and commands
Tag
Description
Example
var
Variable declaration (function scope)
var x = 5;
let
Block-scoped variable
let name = “John”;
const
Constant declaration
const PI = 3.14;
function
Function declaration
Function declarationfunction greet() {}
=>
Arrow function
const fn = () => {};
if/else
Conditional statement
if (x > 0) { … }
for
For loop
for (let i = 0; i < 10; i++)
while
While loop
while (condition) { … }
object
Object literal
{ name: “John”, age: 30 }
class
Class declaration
class MyClass { … }
import/export
Module system
import { fn } from “./file”;
async/await
Asynchronous operations
async function() { await … }
try/catch
Error handling
try { … } catch(e) { … }
Promise
Promise object
new Promise((resolve) => …)
Python Reference
Quick reference for Python syntax and commands
Tag
Description
Example
class MyClass:
if/elif/else
Conditional statements
if x > 0: …font-family: Arial;
for
For loop
for i in range(10):
while
While loop
while condition:
list
List operations
[1, 2, 3].append(4)
dict
Dictionary
{“key”: “value”}
import
Import modules
import numpy as np
height
Element height
<span class=”highlight”>
try/except
Exception handling
try: … except: …
with
Context manager
with open(“file”) as f:
lambda
Anonymous function
lambda x: x * 2
comprehension
List comprehension
[x*2 for x in range(10)]
decorator
Function decorator
@decorator
SQL Reference
Quick reference for SQL syntax and commands
Tag
Description
Example
SELECT
Retrieve data
SELECT * FROM users;
INSERT
Add new records
INSERT INTO users (name) VALUES (“John”);
UPDATE
Modify existing records
UPDATE users SET name = “Jane”;
DELETE
Remove records
DELETE FROM users WHERE id = 1;
CREATE TABLE
Create new table
CREATE TABLE users (id INT);
ALTER TABLE
Modify table structure
ALTER TABLE users ADD email;
DROP TABLE
Delete table
DROP TABLE users;
WHERE
Filter records
SELECT * WHERE age > 18;
ORDER BY
Sort results
ORDER BY name ASC;
GROUP BY
Group results
GROUP BY category;
JOIN
Combine tables
SELECT * FROM a JOIN b ON a.id = b.id;
LIMIT
Limit results
LIMIT 10;
HAVING
Filter groups
HAVING COUNT(*) > 5;
PRIMARY KEY
Unique identifier
id INT PRIMARY KEY
Quick Tips
Keyboard Shortcuts
Learn common IDE shortcuts to code faster. Ctrl+S to save, Ctrl+F to find, Ctrl+Z to undo.
Code Formatting
Use consistent indentation and formatting. Most editors have auto-format features.
Debugging
Use console.log() or debugger statements to trace and fix issues in your code.